The present disclosure relates to an image forming apparatus configured to form an image on a sheet conveyed along a conveying path by a conveying roller pair.
In image forming apparatus such as a printer and a color printer, a toner image is transferred on a sheet from an image carrier at a transfer nip formed between the image carrier and a transfer roller. On a sheet conveying path toward the transfer nip, a resist roller pair which adjusts a sheet conveying timing is installed. By stopping the rotation of the resist roller pair, a nip is formed between the resist rollers and a front edge of the sheet is abutted against the nip. Then, the sheet deflects in such a way that the front edge of the sheet is aligned along the nip. This collect a skew of the sheet. After that, the resist roller pair is rotated to convey the sheet by synchronizing with the toner image transfer timing at the transfer nip.
The sheet is fed from a sheet feeding cartridge or a manual sheet feeding unit. In recent years, with a diversification of type of the sheet, a plurality of sheet feeding cartridges for each type of the sheets are often prepared. The sheet feeding cartridges are arrayed vertically in general. In a case when a thin sheet is stored in a lower sheet feeding cartridge, there is a problem that wrinkles caused by waving of the sheet is occurred at the skew collecting by the registration roller pair because the thin sheet is not stiff.
Then, in order to prevent the occurrence of such wrinkles, there is an image forming apparatus provided with a guide plate on an upstream side from the resist roller pair in a sheet conveying direction. In the image forming apparatus, when a front edge of a sheet abuts against the guide plate, the guide plate turns corresponding to stiffness of the sheet and deflects the sheet corresponding to a thickness of the sheet.
However, in the image forming apparatus described above, because the guide member is disposed such that the front edge of the sheet abuts against the guide member, it is necessary to form the conveying path on an upstream side of the resist roller pair into a curved path. As a result, there is a problem that a length of the conveying path becomes long and thus the size of the image forming apparatus becomes large.